Effect of the cathode material on the removal of nitrates by electrolysis in non-chloride media

JOURNAL OF HAZARDOUS MATERIALS

卷:213

Article

Lacasa, Engracia¹  Canizares, Pablo¹  Llanos, Javier¹  Rodrigo, Manuel A.¹ 

[1] Univ Castilla La Mancha, Fac Chem Sci, Dept Chem Engn, E-13071 Ciudad Real, Spain

关键词: Electrolysis;    Conductive diamond electrodes;    Nitrates;    Reduction;    Water treatment;   

DOI  :  10.1016/j.jhazmat.2012.02.034

来源: Elsevier

【 摘 要 】

In this work, the effect of the cathode material (conductive diamond, stainless steel, silicon carbide, graphite or lead) and the current density (150-1400 A m(-2)) on the removal of nitrates from aqueous solutions is studied by electrolysis in non-divided electrochemical cells equipped with conductive diamond anodes, using sodium sulphate as the electrolyte. The results show that the cathode material very strongly influences both the process performance and the product distribution. The main products obtained are gaseous nitrogen (NO. N2O and NO2) and ammonium ions. Nitrate removal follows first order kinetics, which indicates that the electrolysis process is controlled by mass transfer. Furthermore, the stainless steel and graphite cathodes show a great selectivity towards the production of ammonium ions, whereas the silicon carbide cathode leads to the highest formation of gaseous nitrogen, which production is promoted at low current densities. (C) 2012 Elsevier B.V. All rights reserved.

【 授权许可】

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